1. Field of the Invention and Related Art Statement
The present invention relates to a three-way ball valve used for mixing cold water and steam or hot water to make warm water. Such warm water is used for bathing, showering and other household uses and the like.
2. Description of the Background Information
According to the common usage, the "ball valve" used herein means a type of cocks having a flow controlling spherical plug hereinafter designated as a "valve". Such ball valves have the characteristic features that the annular valve seats thereof are surfaces of revolution, and that there is negligible thrusting force acting in the direction of the valve stem.
The most important function of the mixing device is, of course, achieving a good mixing of the water. It is an easy matter to mix two fluids thoroughly by the use of complex and expensive device; it is, however, quite another problem to achieve this in a small constrained space like in the valve chamber of the present invention. The inventor has proposed in Japanese Pat. No. 1139147, a three-way ball valve for mixing cold water and steam which can minimize fluctuation of the mixing ratio of the two fluids, that is, minimize the temperature of the mixed fluid regardless of time or place. Unfortunately, the valve of this type necessitates a poppet valve in addition to the flow controlling ball valve. A three-way ball valve which does not include the poppet valve, which still attains the same level of performance is desirable.